California prisons hold around 30,000 fewer inmates today than 30 months ago, the result of AB 109’s Public Safety Realignment. Realignment mandated that as of October 1, 2011, tens of thousands of non-violent, lower-level offenders who formerly would have been sent to state prison must be “realigned” to local criminal justice systems.

Still, it’s legitimate to ask how a major public policy like Realignment might affect crime, especially given the irony that the lower-level drug and property offenders affected tend to have high recidivism rates no matter who supervises them. A recent Public Policy Institute study linked Realignment to increased property crime but not violence. However, lots of factors affect crime rates. How can we determine whether Realignment caused or contributed to 2012’s crime increase?

The method we at the Center on Juvenile and Criminal Justice developed is to analyze rates and trends by county. California’s 58 counties provide a wide variety of population sizes, demographics, policy innovations and implementations, administrative competencies, and other variables that make them laboratories for studying policy. Our analysis divided California’s counties into “high realignment” and “low realignment” categories based on their proportion of realigned population relative to the state average.

Our study found that most counties showed large decreases in prison admissions, some of 50% or more, after Realignment, others had only small declines, and three showed increases. Counties also faced widely divergent tasks in handling thousands of state prison parolees assigned to local jurisdictions under Realignment guidelines.

Added together, the numbers of realigned offenders and parolees, expressed as a percentage of all felons in a particular county, varied from under 5% in San Francisco to 35% in Kings County. Several smaller counties showed greater extremes. Counties also showed large divergences in crime trends.

If Realignment underlies the increase in crime, we would expect counties with higher proportions of realigned offenders in their total felon populations would suffer worse trends in crime. Our study found no definitive association. The 25 counties with higher than average proportions of realigned offenders did not have any unusual increase in violent crime, but did have a somewhat larger than average increase in property crimes. However, county trends were so variable that trends were not significant.

What is striking is the divergent trends in homicide. Homicide rates declined by an average of 7% in counties with greater proportions of realigned offenders, but increased in counties with lower shares of realigned offenders by 17%. That more realignment accompanied less murder contradicts what alarmist opponents of Realignment have proclaimed.

But a complication intrudes: counties with more realigned offenders also had more offenders in state prison or on state parole, a consequence of their greater dependence on the state system prior to Realignment. So, did their increase in property crime and decline in murder result from more realigned offenders, more state-managed offenders, or both, or something else?

We found self-reliant counties (those that generally handled more of their offenders locally) tended to have more favorable trends in 2012 than state-dependent counties for both violent and property crime. Perhaps this is due to self-reliant counties having developed more innovative local strategies. However, that issue, too, remains complicated.

The bottom line is that California has no viable alternative to making Realignment work. California should not haphazardly implement major modifications to Realignment based on anecdotes and assertions. The courts, the voters, policy makers, and researchers agree that massive imprisonment is inhumane, unconstitutional, self-defeating, and budget-busting.

The many, diverse counties that are locally managing higher numbers of realigned offenders without increased crime serve as potential models of successful policy. Any effective policy must recognize the varied 58 county experiences with Realignment and the need for greater state oversight, data collection, and funding resources to help counties succeed.